Interest in population-screening programs for abnormal hemoglobins in the United States has increased primarily because of the National Sickle Cell Disease Program developed by the Department of Health, Education and Welfare. Thus, screening for hemoglobinopathies has become very important within the past five years. For example, many hospitals now screen all incoming surgical patients for such abnormalities. Because electrophoresis on cellulose acetate is the primary procedure used in the Federal Sickle Cell Disease Program, cellulose acetate electrophoresis at pH 8.4-9.2 currently is the most common electrophoretic screening method for hemoglobinopathies. It has been found, however, that cellulose acetate cannot adequately separate certain combinations of hemoglobin variants. See for example, E. J. Hicks and B. J. Hughes, Clin. Chem., 21, 1072 (1975). Thus, in questionable cases, one must proceed to a secondary procedure such as electrophoresis on citrate agar to obtain a more definitive diagnosis.
The separation of hemoglobins A and F on an agar gel using a barbital buffer of pH 8.6 and ionic strength 0.03 has been reported, but at least one worker in the field questions the data, stating that at alkaline pH the separation of such two hemoglobins was impossible because of complex formation between the hemoglobins.
A hemoglobin screening system involving agarose gel electrophoresis currently is marketed by Corning Medical (Corning Glass Works, Medfield, Mass.), which separates hemoglobins at pH 8.6 by use of a discontinuous buffer system utilizing 2-amino-2-methyl-1-propanol. Such procedure, however, does not adequately resolve the common hemoglobin variants A, F, S and C.
Consequently, there still is a need for a rapid and simple electrophoretic procedure for the separation of the common hemoglobin variants.